The present invention relates to a new and improved construction of door arrangement, especially for a residential structure, particularly for closing the entrance of an apartment or home, comprising a door frame formed of metal hollow sections or profile members inserted into the door opening and a single-wing door faced or lined with coverings and composed of metal hollow sections or profile members, and further having internally situated hinges and a door lock having a locking bolt and catch.
With door arrangements conventionally employed for closing a residence, such as an apartment or a house, the door usually consists of wood or a material formed on the basis of wood, whereas the fixture of the door opening is formed of a frame of wood or metal. The door which usually opens towards the inside has a rectangular shoulder or projection at its edge which, when the door is closed, bears against the side of the frame confronting the interior of the apartment or house.
This prior art door arrangement is particularly associated with the drawback that when forced from the outside, for instance during a burglary or unauthorized entry, the applied forces must be taken up on the one hand by the locking bolt of the lock and on the other hand by the hinges of the door. The high specific pressures which occur either cause tearing away of the hinges at the door or at the frame, as the case may be, or tearing away of the counter-holder of the locking bolt at the frame or at the lock in the door, respectively. Also, it is possible that the frame, which as a general rule is not particularly anchored, can loosen from the edge of the door opening.
Certain improvements have been attained inasmuch as, on the one hand, the doors are partially fabricated from metal hollow sections faced or lined with coverings and, on the other hand, the frames likewise fabricated of metal hollow sections are anchored at the edge of the door opening. Additional improvements can be realized by welding the hinges. While with all of these measures the strenght of the door, the lock and the hinges, is increased, still the basic problem remains that the pressure, when applying an external force to the door, essentially is concentrated at three points.